[atq2119]

I suspect it is in part the combination of academia being a somewhat "normatively standard" path for people to take but, unlike most other such paths, inherently requires a lot of self-discipline and self-motivation. The result is that mental health issues may cause worse extreme outcomes, for the sort of person who can go into a PhD. The "standard" alternative path for somebody like that is some office job where you can just sort of muddle through: you may be deeply unhappy, but the money still comes in and it's easier to find satisfaction in other aspects of your life.

There are other paths where self-discipline and self-motivation are important, like being an independent consultant, but those are generally not considered "normatively standard" paths for people to take.

(My personal experience with academia was great. I was genuinely interested in the topics, had great colleagues and a great advisor. It probably helped that it was in maths, where there is money for decent pay but no lab work with which PhD students are routinely burdened.)